This invention relates to optical-to-electrical and electrical-to-optical modules and more particularly to electrical mounting features in such modules.
In optical-to-electrical and electrical-to-optical (hereinafter xe2x80x9coptoelectricxe2x80x9d) modules used in the various communications fields, one of the most difficult problems that must be solved is the electrical interconnection of the various components and the shielding of the module to prevent radiation, (e.g., electromagnetic interference (EMI)) into or out of the module. Providing this efficient interconnection and shielding requires very precise assembly procedures. Here it will be understood by those skilled in the art that the term xe2x80x9clightxe2x80x9d, as used throughout this disclosure, is a generic term which includes any electromagnetic radiation that can be modulated and transmitted by optical fibers or other optical transmission lines.
Much of the optoelectric module fabrication difficulty and expense is due to mounting and shielding difficulties of optical components, such as lasers, light emitting diodes, photodiodes, etc. Generally, there are two types of lasers that are used in optoelectric modules, edge emitting lasers and surface emitting lasers. Edge emitting lasers emit light in a path parallel to the mounting surface while surface emitting lasers emit light perpendicular to the mounting surface. The light from either of the lasers must then be directed into an optical fiber for transmission to a remotely located light receiver (i.e., a photodiode or the like). Lens systems are used at both ends of the optical fiber to direct light from a light generating component into the optical fiber and to direct light from the optical fiber onto a light sensing component. The apparatus used to mount the optical components and the lens systems can have a substantial effect on the construction of the optical systems and the assembly procedures for the optical systems. Also, the mounting structure for the optical components and the lens system must be very rugged and stable so that alignment is not disturbed by use or temperature changes. Further, the entire module must be shielded from external signals and the like and to prevent radiation to other external devices or modules.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
Accordingly, it is an object the present invention to provide new and improved optical component mounting and interconnect apparatus.
Another object of the present invention is to provide new and improved optical component mounting and interconnect apparatus which is rugged and stable.
Another object of the present invention is to provide new and improved optical component mounting and interconnect apparatus which is shielded to prevent radiation into and/or out of the module.
And another object of the present invention is to provide new and improved optical component mounting and interconnect apparatus which improve the fabrication efficiency and manufacturing capabilities of optoelectric modules.
Still another object of the present invention is to provide new and improved optical component mounting and interconnect apparatus which allows the use of a variety of optical components and component materials.
Still another object of the present invention is to provide new and improved component mounting and interconnect apparatus which is designed to reduce outside interference with the desired signal.
Briefly, to achieve the desired objects of the present invention in accordance with a preferred embodiment thereof, provided is a TO-can-type optoelectric assembly including a TO-can having a first end with an optical element therein for conducting light therethrough and a second end, the first and second ends defining an optical axis. A base is affixed to the second end of the TO-can and a laser is affixed to the base so that light generated by the laser is directed through the optical element in the first end generally along the optical axis. A laser driver is affixed to the base and electrically connected to the laser by either electrical traces on a surface of the base, vias through at least a portion of the base, or flexible leads mounted at least partially on the base, and external connections are made to the laser driver by either electrical traces on a surface of the base, vias through at least a portion of the base, or flexible leads mounted at least partially on the base.
The above and other objects of the present invention are further realized in accordance with another embodiment in which an optoelectric assembly includes a first semiconductor chip with one of a laser and an optical detector fabricated thereon. A second semiconductor chip includes one of a laser driver and an amplifier, depending upon the device fabricated on the first chip. The first semiconductor chip is mounted on the second semiconductor chip, by bump bonding or the like, so that the one of the laser and the optical detector are physically and electrically connected to the one of the laser driver and the amplifier, respectively. A base has the second semiconductor chip affixed thereto and includes external connections to the second semiconductor chip by either electrical traces on a surface of the base, vias through at least a portion of the base, flexible leads mounted at least partially on the base, combinations of the above, or similar structures.
The above and other objects of the present invention are further realized in accordance with another embodiment in which an optoelectric module includes a cylindrical ferrule defining an optical axis and having a first end constructed to receive an optical fiber aligned along the optical axis, A TO-can is positioned within the ferrule and has a first end with an optical element therein for conducting light therethrough with the first and second ends positioned along the optical axis. A base is affixed to the second end of the TO-can and to the second end of the ferrule. A laser is mounted on the base within the TO-can so that light generated by the laser is directed through the optical element in the first end generally along the optical axis. A laser driver is mounted on the base and electrically connected to the laser by either electrical traces on a surface of the base, vias through at least a portion of the base, or flexible leads mounted at least partially on the base and external connections are made to the laser driver by either electrical traces on a surface of the base, vias through at least a portion of the base, or flexible leads mounted at least partially on the base.